Effect of Zonal Structure of Some Fibers on the Penetration Thermokinetics

Abstract

Studies have been carried out on the thermokinetics of penetration of suitable selected liquids into cellulose, protein and polyvinyl alcohol fibers. The selection of penetrants was made on the basis of a previous finding that some liquids penetrate slowly into the accessible regions of particular types of fibers.

The thermokinetics of the action of these liquids on fibers of mono- and bizonal structures has been studied.

It has been found that, in the case of monozonal fibers the shape of thermogram is a result of, at least, two penetration processes which proceed at different rates, namely, a relatively quick penetration of liquid into interfibrillar spaces (micropores) and a slow penetration into intermolecular regions (intermolecular diffusion). As a result, “head-tail” and “two-maxima” type composite thermograms are obtained. The former is mostly common for monozonal fibers. In the case of bizonal fibers, the shape of the thermograms is dependent, first of all, on the fiber group. The thermograms have mostly two maxima. However, it is difficult to find a relation between the zonal structure of fiber and the shape of thermograms on the basis of a quality assessment. Examination of changes in the thermogram shape in the case of annealed samples or analysis of thermograms of the action of concentrated NaOH solution on fibers allow to find a closer relationship between the shape of thermograms and the zonal structure of fibers.